Multiple choice

A can do a work in 36 days and B in 12 days. If they work on it together for 3 days, then what fraction of work is left?

  1. 2/3

  2. 1/3

  3. 1/4

  4. 1/5
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A's work per day = 1/36. B's work per day = 1/12. Together = 1/36 + 3/36 = 4/36 = 1/9. In 3 days, they do 3 * (1/9) = 1/3. Work left = 1 - 1/3 = 2/3.

AI explanation

Using the combined work formula, A and B together complete 1/36 + 1/12 of the work in one day, which is 4/36 or 1/9. In 3 days, they complete 3 multiplied by 1/9, amounting to 1/3 of the task. The fraction of the work remaining is 1 minus 1/3, which equals 2/3.

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